Sinodrills Symmetric/Centrex/Symmitrix Drilling System

Symmetric is a concentric drilling system with retrievable pilot bits.
This system drills in any direction and in any type of ground condition.
It is, in fact, the most flexible and efficient overburden system on the market today.

The Symmetric components are made up of:
---A pilot bits with large internal flushing holes and external flushing grooves
---Symmetrical ring bit (reamer) with internal bayonet coupling
---Casing shoe for driving of casing.
The Pilot bits is attached to any common DTH hammer shank.